Matt Corallo [ARCHIVE] on Nostr: 📅 Original date posted:2023-02-14 🗒️ Summary of this message: The Lightning ...

📅 Original date posted:2023-02-14
🗒️ Summary of this message: The Lightning Network faces a challenge in creating a reputation system due to the rarity of repeat interactions, but a solution could be for wallet vendors to provide live network views.
📝 Original message:
On 2/13/23 7:05 PM, ZmnSCPxj wrote:
> Good morning all,
>
>>> First of all let's see what types of reputation system exist (and yes,
>>> this is my very informal categorization):
>>>
>>> - First hand experience
>>> - Inferred experience
>>> - Hearsay
>>>
>>> The first two are likely the setup we all are comfortable with: we ourselves
>>> experienced something, and make some decisions based on that
>>> experience. This is probably what we're all doing at the moment: we
>>> attempt a payment, it fails, we back off for a bit from that channel
>>> being used again. This requires either being able to witness the issue
>>> directly (local peer) or infer from unforgeable error messages (the
>>> failing node returns an error, and it can't point the finger at someone
>>> else). Notice that this also includes some transitive constructions,
>>> such as the backpressure mechanism we were discussing for ariard's
>>> credentials proposal.
>>>
>>> Ideally we'd only rely on the first two to make decisions, but here's
>>> exactly the issue we ran into with Bittorrent: repeat interactions are
>>> too rare. In addition, our local knowledge gets out of date the longer
>>> we wait, and a previously failing channel may now be good again, and
>>> vice-versa. For us to have sufficient knowledge to make good decisions
>>> we need to repeatedly interact with the same nodes in the network, and
>>> since end-users will be very unlikely to do that, we might end up in a
>>> situation were we instinctively fall back to the hearsay method, either
>>> by sharing our local reputation with peers and then somehow combine that
>>> with our own view. To the best of my knowledge such a system has never
>>> been built successfully, and all attempts have ended in a system that
>>> was either way too simple or is gameable by rational players.
>>
>>
>> In lightning we have a trivial solution to this - your wallet vendor/LSP is already extracting a fee
>> from you for every HTLC routed through it, it has you captive and can set the fee (largely)
>> arbitrarily (up to you paying on-chain fees to switch LSPs). They can happily tell you their view of
>> the network ~live and you should generally accept it. Its by no means perfect, and there's plenty of
>> games they could play on, eg, your privacy, but its pretty damned good.
>>
>> If we care a ton about the risks here, we could have a few altruistic nodes that release similar
>> info and users can median-filter the data in one way or another to reduce risk.
>>
>> I just do not buy that this is a difficult problem for the "end user" part of the network. For
>> larger nodes its (obviously, and trivially) not a problem either, which leaves the "middle nodes"
>> stranded without good data but without an LSP they want to use for data. I believe that isn't a
>> large enough cohort to change the whole network around for, and them asking a few altruistic (let's
>> say, developer?) nodes for scoring data seems more than sufficient.
>
> But this is all ultimately hearsay.
>
> LSPs can be bought out, and developers can go rogue.
> Neither should be trusted if at all possible.

You're missing the point - if your LSP wants to "go rogue" here, at worst they can charge you more
fees. They could also do this by...charging you more fees. I'm not really sure what your concern is.

> Which is why I think forwardable peerswaps fixes this: it *creates* paths that allow payment routing, without requiring pervasive monitoring (which is horrible because eventually the network will be large enough that you will never encounter the same node twice if you're a plebeian, and if you're an aristocrat, you have every incentive to lie to the plebeians to solidify your power) of the network.

No, this is much, much worse for the network. In order to do this "live" (i.e. without failing a
payment) you have to establish trust relationships across the network (i.e. make giving your peers
credit a requirement to be considered a "robust node" and, thus, receive fee revenue).

Doing splicing/peerswap as a better way to rebalance is, of course, awesome, but it doesn't solve
the issue of "what do I do if I'm just too low on capacity *right now* to clear this HTLC".

Matt